A sound wave is a longitudinal mechanical wave. This means the particles of the medium through which the sound travels (such as air, water, or solids) oscillate back and forth in a direction parallel to the direction the wave is moving. These oscillations create alternating regions of compression (high pressure) and rarefaction (low pressure) that propagate through the medium
. Key points about sound waves:
- Longitudinal wave: Particle motion is parallel to wave propagation, similar to pushing and pulling a slinky
- Mechanical wave: Sound requires a medium (air, water, solids) to travel because it moves by particle-to-particle vibrations; it cannot travel through a vacuum
- Pressure wave: The wave consists of fluctuations in pressure due to compressions and rarefactions
- Energy transfer: The particles themselves do not travel with the wave but oscillate around their equilibrium positions, transferring energy through the medium
Thus, sound waves are longitudinal mechanical pressure waves characterized by particle vibrations parallel to the wave direction and pressure variations in the medium.
